The invention is directed to a coated seed for bypassing the entire ruminant digestive tract, a method for coating such seeds, and a method for sowing bypassed seeds on a plot of grazing land.
Cattle, sheep, and other agriculturally important livestock are ruminants or cranial fermentors. These animals all have a rumen, which is a large, multicompartmented section of the digestive tract between the esophagus and the true stomach. The rumen contains a very complex ecosystem made up of cellulolytic microbes that, unlike multicellular organisms, are capable of digesting the cellulose that makes up a large part of a ruminant""s diet.
The microbes in the rumen are essential for the digestion, through fermentation, of the large amounts of fibrous feeds that ruminants consume, but cannot otherwise efficiently utilize. Ruminants are able to utilize the end products of microbial fermentation and biosynthesis to meet their own nutritional needs.
However, having a rumen can adversely affect the nutritional physiology of these animals. Passage through the rumen can chemically change nutrients or medicaments that are fed to a ruminant. For instance, ruminants cannot directly utilize simple sugar sources of nutrition. Instead, simple sugars are fermented in the rumen to volatile fatty acids, which are then used by the ruminant. Also, essential amino acids are deaminized to ammonia and microbial proteins.
Nutrients and medicaments may have deleterious effects on the ecosystem of the rumen. For example, feeding fatty acids at above a 3% level to a ruminant can reduce the microbial growth rate of the cellulolytic microflora in the rumen. Furthermore, antibiotics can also depress growth of cellulolytic microbes in the rumen.
Nutritional restrictions associated with the rumen have prompted much work in the field of rumen-bypass products. Typical rumen-bypass products are protected from digestion in the rumen but are digested and absorbed in the lower portions of the ruminant digestive tract.
U.S. Pat. No. 4,642,317 to Palmquist, et al. discloses a process and composition for supplying fatty acids as nutrients to ruminants by feeding calcium salts of the fatty acids. These calcium salts bypass the rumen and are absorbed in the acidic environment of the abomasum and the small intestine.
U.S. Pat. No. 6,229,031 to Strohmaier, et al. disclose rumen bypass feed supplements, which are calcium salts of fatty acids and fatty acid glycerides. The supplements disclosed by Strohmaier, et al. bypass the rumen and are absorbed lower in the ruminant digestive tract.
Other patents disclose substances for protecting nutrients and other biologically active substances. Such protected nutrients and substances bypass the rumen and are released lower in the digestive tract of the ruminant.
U.S. Pat. No. 3,959,493 to Baalsrud, et al. disclose a fatty acid coating that protects biologically active substances during passage through the rumen but releases the active substance in the lower portions of the digestive tract.
U.S. Pat. No. Re. 35,162 to Draguesku, et al. discloses a stomach chamber bypass nutrient comprising a beadlet with two regions, a nutrient region and a region including fats and calcium based compounds. The beadlets disclosed by Draguesku, et al. bypass all four stomachs of the ruminant, but are digested in the remainder of the digestive system.
U.S. Pat. No. 5,928,687 to Meade, et al. disclose a rumen bypass feed supplement containing at least one biologically active material susceptible to inactivation in the rumen and a protective substance that is a glyceride-free mixture of aliphatic fatty acids, impervious to conditions in the rumen but which allow absorption of the biologically active material in the abomasum and the lower gut.
Overgrazing of pastures by livestock is both an ecological and an agricultural concern. The introduction of legumes into native pastures not only improves the quality of the feed, but the remaining legume forage and root nodules increase the nitrogen content and fertility of the over grazed soil. Furthermore, the increased quality of forage will increase livestock performance and the nitrogen percentage in the manure, which will also add nitrogen to the soil. With proper supplementation and introduction of more legumes into the pasture, the rancher will not only improve beef production, but also soil fertility.
Legumes fix nitrogen, making it biologically available, through a symbiotic relationship with Rhizobium bacteria. Each specific legume has a specific species of Rhizobia with which it is optimally symbiotic. Among the species of Rhizobia that form symbiotic relationships with various legumes are Rhizobium trifolli, Rhizobium meliloti, Rhizobium leguminosarum, Rhizobium japonicum, and the recombinant Rhizobia described in U.S. Pat. No. 5,183,759 to Triplett. Without the correct species of symbiotic Rhizobium, a legume will not flourish.
On the other hand, if both a legume and a symbiotic Rhizobium are present in the soil, the Rhizobium will penetrate the root hairs of the legume. Then the Rhizobium will form an infection thread, which allows the Rhizobium to travel into the legume""s root cortex. Specialized plant cells then encase the Rhizobium, which proliferate, change morphology, and begin to fix nitrogen. These collections of specialized plants cells and Rhizobium form the root nodules, which are indicative of healthy legumes.
The benefit of the symbiotic relationship between legumes and Rhizobia has prompted research into this relationship. U.S. Pat. No. 5,586,411 to Gleddie, et al. discloses a method for treating seeds with a phosphate-solubilizing soil fungus and a Rhizobium prior to planting to increase the efficiency of modulation, nitrogen fixation, and legume crop production.
U.S. Pat. No. 6,350,718 to Frisch discloses organic solvents that may be used in seed treatment formulations to increase the viability of seeds in the field by translocating seed treating substances into the seed.
Methods of seeding legumes into established grasses include complete tillage, partial tillage, strip tillage interseeding, and surface broadcast seeding into undisturbed sod. Late winter frost-seeding into undisturbed sod has many potential advantages including renovation without herbicides, reduced labor requirements and energy inputs, shortening of the non-grazing period and a reduction of erosion on sloping sites. No-till planting is generally known in the prior art and can include any process that doesn""t till the soil itself, such as chopping undesirable forage, mowing, and weed control spraying. Typically, no-till planting still requires machinery such as specialized seeders, broadcasters, and drills along with the labor to operate the machinery.
The present invention provides a coated seed that will bypass the entire ruminant digestive tract. This seed is coated with one or more insoluble fatty acid salts to protect it from degradation by conditions in the ruminant digestive tract. During its passage through the digestive system of the ruminant, the mechanical agitation and chemical digestion will open up fissures in the seed coating and allow the seed to germinate once it exits the digestive tract. Therefore, while the coating for the seed is sufficiently durable to pass through the digestive tract without being digested, the coating is not so durable to prevent the seed from germinating.
The coating is produced by first dissolving one or more insoluble fatty acid salts in a non-aqueous solvent. Then the seeds are coated with the mixture of solvent and insoluble fatty acid salts. Once the solvent evaporates, a homogeneous coating of insoluble fatty acid salts remains around the seed. While any type of seed may be coated in such a manner, legume seeds are particularly useful for improving the quality of pasture forage and the nitrogen content of soil.
The coated seed can also contain a supplement of Rhizobia, which is especially useful for legumes. Legume seeds coated with the corresponding symbiotic Rhizobia are commercially available. In the alternative, an uncoated seed can be directly coated with a suspension of Rhizobia. Such Rhizobia coated seeds are further coated with insoluble fatty acid salts as described above to protect both the seed and the Rhizobia from degradation in the ruminant digestive tract.
Feeding a legume seed coated with the corresponding symbiotic Rhizobia and protected by another coating of insoluble fatty acid salts to ruminants will result in efficient dispersion of the seeds when they pass out of the digestive tract of the ruminants. Furthermore, supplementing the legume seed with Rhizobia will increase the efficiency of nodulation, nitrogen fixation, and legume crop production.